The present invention relates generally to structural systems, and more particularly to a tower structure.
Methods and techniques for the design and construction of towers are faced with many problems. Among the problems that are presented include construction difficulties due to tower height and complex component assemblies, the desire to support large loads, the tower height, the weight of the tower, and the external conditions that act upon the tower, such as wind, earthquakes, and the like. All of these factors, among others, affect the tower design and must be considered in order to design and construct a tower that is constructable yet has the required stability and strength to perform the desired task. As the height of the tower increases, the above-described problems are amplified and the tower design becomes more economically unfeasible due to the size of the tower components, the complexity of the tower design, and the cost of the tower versus the benefit obtained with the increased tower height.
The design and construction of tower structures has been the subject of prior art patents. For example, U.S. Pat. No. 3,368,319 to Werner et al. describes a tower having a triangular truss cross-section with three legs and continuous Warren bracing interconnecting the legs. The legs have a modified channel cross-section to provide a two-to-one ratio of radius of gyration about different axes. A number of anchored guide wires are connected to each of the corner columns at various heights along the tower.
U.S. Pat. No. 5,072,555 describes a super high-rise tower formed from a central rigid core supported by a pretensioned cable network around the core. U.S. Pat. No. 5,097,647 describes the support tower for communication equipment having three generally parallel legs positioned to form a triangular cross-section. Cross bracing is provided to secure the legs one to another intermediate the ends of the legs to provide lateral support for the tower. U.S. Pat. No. 1,235,332 to Lachman describes a pole having a T-bars, Y-bars or channel bars forming the main corner columns of the pole section. These bars are connected by lateral members. U.S. Pat. No. 3,550,146 to Eberle; U.S. Pat. No. 3,062,336 to Baxter; and U.S. Pat. No. 5,649,402 to Moore, each describe other types of tower designs for supporting communication equipment, electrical distribution equipment and the like.
While the prior art patents demonstrate many different attempts to address the problems in tower design and construction, the need for improvement remains. There remains a need for a tower for supporting communications equipment and other types of equipment at distances above the ground that utilizes an efficient and constructable structural support system. The structural support system should also be suited for the design and construction of towers having a height greater than four hundred feet, although the structural system should also have application in shorter tower design and construction. The present invention is directed towards meeting these needs, among others.
The present invention is directed to a tower structure for supporting communications equipment or other types of equipment above the ground. The structure includes a foundation, a tower supported by the foundation that has a number of tower sections, and a cable support structure connected to the tower and anchored to the ground.
In one form, the present invention includes a structure for supporting an object above the ground. The structure includes a foundation and a tower supported by the foundation. The tower has a number of sides each extending between paired ones of a number of corner columns. Each of the sides including at least one intermediate column between paired corner columns. An anchored cable support system extends between the ground and the tower. The cable support system includes a plurality of cable sets connected to the tower with at least one cable set on each side of the tower. Each of the at least one cable sets have a first cable connected to one of the paired corner columns, a second cable connected to the other of the paired corner columns, and a third cable connected to the at least one intermediate column. In one embodiment, the tower has a triangular cross-section and there are two intermediate columns between paired ones of the corner columns. Each of the at least one cable sets includes a fourth cable connected to the other of the two intermediate columns.
In another form of the present invention, a structure for supporting an object above the ground is provided. The structure includes a foundation and a tower supported by the foundation. The tower has a first corner column, a second corner column, and a third corner column and a first side extending between the third corner column and the first corner column, a second side extending between the first corner column and the second corner column, and a third side extending between the second corner column and the third corner column. Each of the three tower sides includes a first intermediate column and a second intermediate column between the corner columns. A main bracing system on each of the sides extends between the first and second intermediate columns. A first sub-bracing system on each of the sides extends between the first intermediate column and an adjacent one of the corner columns. A second sub-bracing system on each of the sides extends between the second intermediate column and the other of the corner columns. An anchored cable support system is connected to the tower.
In one embodiment, a first internal sub-bracing system extends between the second intermediate column of the first side and the first intermediate column of the second side. A second internal sub-bracing system extends between the second intermediate column of the second side and the first intermediate column of the third side. Also, a third internal sub-bracing system extends between the second intermediate column of the third side and the first intermediate column of the first side.
In yet another form of the present invention, a structure for supporting an object above the ground is provided. The structure includes a foundation and a tower supported by the foundation. The tower includes a number of tower sections each having a first corner column, a second corner column, and a third corner column. A first side extends between the third corner column and the first corner column, a second side extends between the first corner column and the second corner column, and a third side extends between the second corner column and the third corner column. Each of the sections includes a first truss, a second truss, and a third truss having a triangular cross-section defined by the first corner column, a first intermediate column on one side and a second intermediate column on an adjacent side. Each truss includes a first sub-bracing system extending between the first intermediate column and the corner column and a second sub-bracing system extending between the second intermediate column and the corner column.
In one embodiment, there is further provided a first main bracing system extending between and coupled to the first truss and the second truss; a second main bracing system extending between and coupled to the second truss and the third truss; and a third main bracing system extending between and coupled to the first truss and the third truss. In a further embodiment, each truss includes an internal bracing system extending between the intermediate columns.
These and other objects, advantages, forms, aspects, and features the present invention will be apparent from the following description.